1. Field of the Invention
This invention relates to a package, that is a packaged article, obtained by wrapping an article with a packaging film, and a method for wrapping an article with the packaging film. More particularly, it relates to a packaged article obtained by wrapping a film around the entire periphery of an article and heat-shrinking the film in its entirety for wrapping the article in a hermetically sealed condition, and a method for wrapping the article using such heat-shrinkable film.
2. Description of the Related Art
There has hitherto been known a method for wrapping an article 2 under an hermetically sealed condition by a heat-shrinkable packaging film 1, as shown in FIGS. 1 and 2. As the film 1, a transparent bi-axially stretched polypropylene film (OPP), having a thickness on the order of 25 to 30 .mu.m, is generally employed. A severing tape 3 is connected to the inner surface of the film 1 for tearing the film 1 for taking out the packaged article 2.
That is, the packaging film 1 is cut to an outer size slightly larger than the developed size of the article 2 and wrapped around the entire periphery of the article 2 so that both longitudinal ends 4, 5 of the film are overlapped with each other, while outer transverse lateral sides of the film 2 are also folded on the outer lateral sides of the article 2. The ends 4 and 5 of the film 1 are heat-welded to each other, and the film 1 is heat-shrunk by being heated in its entirety by a heat-shrinking unit, not shown, so as to be intimately applied to the article to complete a packaged article 6.
The longitudinal end 5 of the packaging film 1 along the article wrapping direction is formed with a strip-shaped tearing tab 7 and the above-mentioned severing tape 3 is connected to the foremost part of the tearing tab 7 for extending therefrom along the entire length in the article wrapping direction. The proximal end of the tab 7 is formed with a pair of slits 8, 8 for extending towards the main body of the film 1. The distance between the slits 8, 8 along the short sides of the package 2 is selected to be slightly larger than the width of the severing tape 3. The difference in the dimension between the tearing tab 7 and the severing tape 3 along the shorter sides of the package 2 is set so that the severing tape 3 is not positioned off the tearing tab 7 even if a wrapping deviation is produced along the short sides of the package 2 when wrapping the film on the article 2.
With the packaged article 6 obtained by wrapping the packaging film 1 around the article 2 under a hermetically sealed condition, the severing tape 3 may be exfoliated from the packaging film 1 along with the tearing tab 7 and pulled strongly along the wrapping direction for tearing off the film 1 for taking out the article 2. The slits 8, 8 formed in the proximal end of the tearing tab 7 functions as a guide in tearing off the packaging film 1 by the severing tape 3.
With the above-described conventional packaging film 1, there are formed regions A, A on both sides of the tearing tab 7 due to the difference in size from the severing tape 3 along the short sides of the package 2, as shown in FIG. 2, so that, when heat-welding the overlapped ends 4, 5 of the film 1, these regions A, A are heat-fused simultaneously.
Thus, with the above-described packaged article 6, it is extremely difficult to peel the tearing tab 7 having the heat-welded regions A, A off from the film 1, when tearing off the packaging film 1 by the severing tape 3, such that the tearing tab 7 frequently can be exfoliated only by scratching the tab with the finger nail. Besides, it occurs frequently that the severing tape 3 is severed halfway without allowing the film 1 to be torn off to take out the package 2.